Fire hose nozzles are used by fire fighters for supplying water or other liquids to extinguish fires. A common method of extinguishing fires is to direct a flow of liquid, usually water, onto the fire and often the surrounding area. The flow rate may have to be reduced, or increased, depending on the changing character of the fire. The flow is typically delivered in a deluge, also known as a smooth bore flow, or in a fog spray. Typically two separate nozzles are required to achieve these distinct flow types. The deluge provides a straight and solid stream, with maximum reach and penetration. A deluge can be delivered in a relatively precise area thus providing a maximum amount of water into a specific location. The fog spray provides a pattern which can be a straight, aspirated spray, or a wide, aspirated spray with less reach and penetration than a deluge at equivalent supply pressure.
Fire fighters may use the fog to cover a wider area and without the force of a deluge which might scatter burning materials before they are extinguished, thus spreading a fire. They may also use the spray in a very wide pattern to create a shield from the intense heat of a fire. The wide fog pattern also creates a back draft which brings cooler, cleaner air from behind the fire fighter. A wide fog will more quickly lower the heat of a fire by flashing into steam.
Fire fighters may ideally need both flow types for the same fire and may prefer to move from deluge to fog and back. To accomplish this, it has traditionally been necessary to stop the flow and change nozzles.
Certain nozzles in the prior art, hereinafter referred to as combination nozzles, include both a deluge and a spray. Combination nozzles of the prior art were intended to overcome the limitations of having to change single nozzles or use two different hoses simultaneously when two patterns were needed. However, combination nozzles of the prior art have several drawbacks. Most combination nozzles of the prior art have a fixed fog pattern around a fixed deluge. They cannot produce a straight fog spray, nor can the fog and deluge operate independently of each other. The most critical drawback affects all combinations of the prior art. They are simply two nozzles stuck together. Due to the limitations of this design, when the second nozzle is enabled after the first nozzle is flowing, the pressure to the nozzle instantly decreases to a level which significantly and negatively impacts the reach and stream quality of the nozzle. This dangerous condition for the nozzle operator can only be addressed by the pump operator. However, communication between the pump operator and the nozzle operator is not reliable during an emergency, and therefore, this dangerous situation can exist for long periods. Coordination between the pump operator and nozzle operator is further complicated by the presence of multiple nozzle operators connected to a common pump each capable of changing the hydraulic conditions the pump operator must overcome. Additionally, when one nozzle is shut down after both nozzles have successfully been adjusted for simultaneous operation, the result is a sudden and unwelcome rise in pressure that increases the nozzle reaction. This is a force the nozzle operator must combat to hold on to the nozzle. This too is a dangerous situation that must be addressed by the pump operator with the aforementioned communication and coordination difficulties.
Thus there exists a need for an apparatus and method which permits quick, efficient and convenient operation of a fire hose nozzle in deluge mode, fog mode, or both. Furthermore, it would be desirable for the fire fighter to be able to adjust the flow rates such that the flow rates can be reduced or increased to balance flow between the deluge and fog modes, thereby avoiding the previously described “dangerous conditions.” The invention described herein provides such a nozzle.